After the Giants' waterfront ballpark opened in 2000, it was held up as a national model for how to build a privately financed professional sports facility.

Opponents of publicly financed ballpark efforts in St. Louis and Minnesota cited it as the exemplar. Veterans of San Francisco's bitter land-use wars say that, after earlier false starts, it was done the right way. The ballpark is also credited with being the catalyst for transforming a faded patch of waterfront into a thriving neighborhood with new condominiums and stylish restaurants.

Now, as the Golden State Warriors seek to build their own bayfront venue a half mile north, supporters regularly draw comparisons between the arena and the ballpark in hopes that it will be just as successful and face minimal opposition.

Critics of the arena are equally quick to point out the differences between the projects to highlight what they see as flaws in the process.

While a Warriors spokesman has called the conceptual framework for the arena "a fairly simple deal that is almost the exact same as the deal for AT&T Park," Quentin Kopp, a retired judge and former San Francisco supervisor, has skewered it as a public subsidy for a "professional sports team with its billionaire owners" that is unlike the Giants' agreement.

"There is a dramatic difference," said Sue Hestor, a land-use attorney who represented some neighbors during the ballpark negotiations and has joined residents voicing concerns about crowds, transit and traffic that would be caused by the entertainment and basketball arena proposed for Piers 30-32.

The reality is that both the Giants' ballpark and, on a larger scale, the framework deal for the arena have the sports franchise paying to build the venue itself but include a substantial amount of public money for related costs.

The financial terms of the two deals are similar, with a few significant exceptions, said Roger Noll, professor emeritus at Stanford, and Andrew Zimbalist, professor at Smith College, two accomplished sports economists who reviewed a side-by-side comparison of the agreements.

"The proposal really is more like the deal with the Giants than like other arena deals, including Oakland and San Jose," Noll said, "but the big difference is that the Warriors' deal includes more stuff."

An expansive project

The scope of the Warriors' plan is bigger and more costly than what the Giants built and would cover more than 15 acres on currently city-owned property. It includes a 17,500-seat arena on a rebuilt 13-acre concrete pier that is slowly eroding into the bay, 105,000 square feet of retail and restaurants, a practice facility, terraced public plazas that cover a 630-car parking garage, and a kayak launch. Across the street, the project would include condominiums, more retail, parking and a hotel, city documents show. At least half of the area on the pier would be public open space.

The projected total price tag is $1 billion, including "soft costs" like architecture and engineering expenses, compared with about $358 million for the Giants' ballpark. That figure is in year 2000 dollars.

The arena proposal, to go before the Board of Supervisors budget committee this week, calls for the city to reimburse the Warriors up to $120 million to repair Piers 30-32. The Warriors' plan to build a new pier in the same place, including 306 new pillars and a 3-foot-thick concrete deck.

Without the work, which the city says it can't afford, the port estimates the pier will be condemned in 10 years and projects demolition costs at about $40 million.

The combined appraised value of the piers and the adjacent parcel known as Seawall Lot 330 is $61 million, according to city documents. That's about half the estimated $120 million cost to make Piers 30-32 developable.

"The economic reality is that the cost of that rehab is more than the fair market value of the site," Chief Assistant City Attorney Jesse Smith said.

The deal calls for the city to retain ownership of the pier and lease it to the Warriors for 66 years.

Funds for the city to reimburse the Warriors could come only from revenue generated by the project, including rent credit of about $2 million a year, selling or leasing Seawall Lot 330 to the Warriors for the appraised value of $30 million, and the city's share of future property taxes generated at the site for up to 30 years.

A 'phenomenal deal'

The city used a similar tax mechanism to reimburse the Giants $15 million for the cost of building the ferry landing, waterfront promenade and other public areas around the ballpark. The port also spent $12 million readying the site for construction, including purchasing a state-owned plot and relocating tenants and a maintenance facility.

That combined $27 million public expense is less than a fourth of what the public would pay under the arena proposal.

"Whether it's the Warriors or someone else, we have to fix that pier. No private developer is just going to come along and fix it for us," said Supervisor Jane Kim, whose district includes both AT&T Park and Piers 30-32.

Jennifer Matz, Mayor Ed Lee's point person negotiating the arena agreement, called it "a phenomenal deal for the city."

"It not only rehabilitates a crumbling pier that is a capital liability," Matz said, "but it creates a world-class open space and an entertainment venue for everything from family shows to concerts."

The arena deal also includes mechanisms for the city to potentially benefit from long-term operations on the site through a transfer fee on condominiums, a stadium admissions tax, and a cut of profits known as "participation rent" once the Warriors recover their development costs - all options where specifics still need to be negotiated.

"It could potentially end up being a great deal for the city," Kim said. "We just have a lot of details to work out."

In particular, Hestor said the deal doesn't factor in increased costs to the Muni system for an arena development expected to draw 2 million people a year.

Neighbors are deeply concerned about cleanup after games and other events and traffic that is already gridlocked at commute times. Particularly problematic are days when there would be events at both the ballpark and arena.

A petition on social pressure website Change.org opposing the arena had 214 signatories on Friday out of a target of 5,000.

It's also unclear if the arena could spark the surrounding revitalization that the ballpark did because the area is already more developed, some observers said.

Nathan Ballard, a spokesman for the project, countered that the arena would "create a vibrant sports and entertainment zone" that stretches from AT&T Park to the Ferry Building, filling vacancies in existing and planned buildings while driving the creation of restaurants and boutique stores.

"This arena will fill a missing puzzle piece on the waterfront," Ballard said.

Sports facilities, though, rarely are the best use of public property in terms of return on a city's investment, said Noll, the Stanford sports economist. But public trust restrictions on waterfront development limit housing and office uses at the site, which can be more lucrative.

"Because the city is providing financial incentives for more than just an arena, the potential cost is much greater," Noll said, "but so is the potential benefit."